This invention relates to a method and a device both for continuously laminating onto substrates a transfer layer of a lengthy laminate film comprising a base film and the transfer layer and a cover film which are formed on the base film in this order.
There have been proposed various methods for laminating onto substrates a transfer layer formed on a base film. For example, Japanese Patent Application Unexamined Publication No. 3-205134 (1991) discloses a method wherein first a laminate film is cut at its frontal side perpendicularly to the feeding direction of the laminate film, and after the frontal end part of the laminate film is pressed onto the frontal end part of a substrate relative to the transport direction of the substrate, the laminate film is continuously fed and laminated onto the substrate by lamination rolls. The laminate film is also cut to form a rear end located to give a length corresponding to that of the substrate, and lamination is carried out, with the rear end of the laminate film supported. This method involves the problem that the transfer layer or intermediate layer of the laminate film is thermally fluidized during lamination, and squeezed out from the cut ends of the laminate film, adhering to and contaminating substrates. Further, because the laminate film is laminated after cut to the length between the frontal end and rear end of the substrate, the laminate film is applied with varied tensions and wrinkles due to uneven thickness and deflection. The method involves another problem of low productivity since the temporary attachment of the laminate film prior to lamination temporarily stops the lamination operation and disables speeding up, and the base film should be peeled off after lamination.
Another method is disclosed in Japanese Patent Application Unexamined Publication No. 5-338040 (1993). After the cover film of a laminate film is peeled off, cut-lines are made in the transfer layer with cutters to form boundaries dividing the lamination layer into parts to be attached between the frontal and rear end parts of substrates and other parts not to be transferred, and lamination is carried out, with the cut-lines fitted to substrates. Lamination rolls ceases pressing operation in the region including the frontal and rear end parts of the substrates and the interval between substrates, where lamination is not necessary. After the transfer layer is laminated onto substrates by continuously repeating the lamination operation, the base film of the laminate film is continuously peeled off from the substrates. The base film is peeled off, leaving only the necessary parts of the transfer layer between the cut-lines forming the frontal and rear ends. There is disclosed another method whereby the photosensitive layer to be located at the spaces between substrates is removed previously.
At low operating speeds of about 0.5 to 0.8 m/min, the method prevents the transfer layer from adhering to and contaminating rolls between substrates. However, on high-speed lamination operation (1 to 3 m/min) requiring frequent ON-OFF switching of pressing rolls, the tension of the laminate film varies frequently, so that the laminate film shifts from the predetermined position, causing loss of the position accuracy of lamination, and lamination gets out of the prescribed position between the frontal and rear end parts of a substrate. Consequently, when the base film is peeled off, the cut-lines overlap with the ends of the substrates, whereby the transfer layer on the peeling face becomes difficult to peel off, or the transfer layer that should be attached with pressure to the surface of the substrate is also peeled off. Further, the ON-OFF switching of the pressing rolls varies the tension of the laminate film undergoing lamination, so that the transfer layer laminated on the substrate with pressure tends to have wrinkles and uneven thickness.
This invention provides a lamination device and a lamination method, which are improved in production efficiency because a transfer layer can be laminated speedily and accurately on the desired parts of substrates except the frontal and rear end parts thereof, without causing unevenness or wrinkling, and as well prevent the transfer layer from being squeezed out to form extraneous matter.
The lamination device of this invention comprises:
a mechanism for exposing a transfer layer to be laminated onto substrates to light in a region of the transfer layer corresponding to end parts of a substrate, which end parts are located to laminate the resist onto the substrate between the end parts, and to the space between two substrates, so that the region of the transfer layer does not adhere to lamination rolls nor to the parts of substrates where the transfer of the resist is not required;
a lamination mechanism;
a substrate transport mechanism for feeding substrates to the lamination mechanism at prescribed intervals;
a lengthy laminate film transport mechanism for feeding a lengthy laminate film comprising a base film and a transfer layer formed thereon to the lamination mechanism, so that the transfer layer faces the substrate; and
a peeling mechanism for continuously peeling off the base film after lamination,
wherein the lamination mechanism and the peeling mechanism comprise a pair of lamination rolls facing each other and a guide roll for peeling off the base film, which is located, in the transport direction of the substrates, forward of the lamination roll on the side of the lengthy laminate film.
The first lamination method of this invention comprises feeding, between a pair of lamination rolls facing each other, substrates fed at prescribed intervals and a lengthy laminate film comprising a base film and a transfer layer formed thereon, so that the transfer layer faces the substrate, and continuously peeling off the base film, and is characterized in that, at the frontal end part of each substrate, the base film is peeled off by a guide roll for peeling off the base film, which is located, in a transport direction of the substrates, forward of the lamination roll on the side of the lengthy laminate film and is smaller in diameter than the lamination roll being to be in contact with the lengthy laminate film, and, at a rear end part of each substrate, the base film is peeled off by the lamination roll on the side of the lengthy laminate film.
The diameter of the guide roll for peeling off the base film is preferably at most one-third as large as the diameter of the lamination roll on the side of the lengthy laminate film, and the guide roll for peeling off the base film preferably has a diameter of 30 mm or less.
The lamination roll on the side of the lengthy laminate film is preferably a heating roll, and the guide roll for peeling off the base film is preferably a non-heating roll.
The second lamination method of this invention comprises feeding, between a pair of lamination rolls facing each other, substrates fed at prescribed intervals and a lengthy laminate film comprising a base film and a transfer layer formed thereon, so that the transfer layer faces the substrate, and continuously peeling off the base film, and
is characterized in that vacant spaces are provided between the lamination rolls and the lengthy laminate film by vertically moving the lamination rolls or guide rolls, the guide rolls being located, in the transport direction of the substrates, forward and backward of the lamination roll on the side of the lengthy laminate film, respectively.
It is preferable that, after the vacant spaces are provided between the lamination rolls and the lengthy laminate film by vertically moving the lamination rolls or the guide rolls, a heat shield plate is inserted in at least one vacant space. The heat shield plate preferably has a self-cooling function.
The guide roll located, in the transport direction of the substrate, forward of the lamination roll on the side of the lengthy laminate film preferably doubles as a guide roll for peeling off the base film.
The third lamination method is for continuously laminating onto substrates continuously fed at prescribed intervals a transfer layer of a lengthy laminate film comprising a base film and the transfer layer and a cover film which are formed on the base film in this order, and is characterized in comprising
a step of continuously feeding the lengthy laminate film,
a step of pressing heating bars against the lengthy laminate film from the outer surface of the cover film without cutting the cover film, to give the transfer layer a divided region corresponding to the total of the interval between two substrates and the widths of the end parts of one substrate where lamination is not required,
a step of exposing the transfer layer to light at the region which lies between the heating bars and corresponds to the total of the interval between two substrates and the widths of the end parts of the substrates where lamination is not required,
a step of continuously peeling off the cover film,
a step of laminating the transfer layer onto the substrates, which is continuously fed and arranged at prescribed intervals, so that the divided region of the transfer layer made by the heating bars is positioned on the end parts of the substrates where lamination is not required,
a step of half-cutting the base film on the substrates at the parts pressed by the heating bars, and
a step of peeling off the cut base film together with the transfer layer that was exposed to light.